Effect of reaction temperature on formation of α-Si3N4 nanowires by a simple CVD method

alpha-Si3N4 nanowires were formed by a simple chemical vapor deposition (CVD) method using Si and SiO2 as raw materials without the addition of metal catalyst. The effect of reaction temperature on the phase composition and morphologies of the nanowires were analyzed by XRD and SEM. The experimental results indicate that a suitable reaction temperature is essential for the final products. At 1400 degrees C, small amount of target products were obtained, and some irregular particles were attached on the surfaces of nanowires. When the temperature increased to 1450 degrees C, the nanowires were mainly composed of alpha-Si3N4 phase, they had smooth surfaces with diameters fluctuating from 50 to 200 nm and lengths from hundreds to thousands of microns. At further high reaction temperature (1500 degrees C), beta-Si3N4 phase was observed and the nanowires had larger diameters, this was negative for obtaining purity alpha-Si3N4 nanowires. The growth process of alpha-Si3N4 nanowires was dominantly governed by the vapor-solid mechanism.

Automated summary

Alpha-Si3N4 nanowires were successfully synthesized by a simple chemical vapor deposition method using Si and SiO2 as raw materials without the addition of metal catalyst. The reaction temperature was found to play a crucial role in determining the phase composition and morphologies of the nanowires.